Bag and method of making same



Sept. 14, 1937.

C. F. RICHARD BAG AND METHOD OF MAKING SAME Filed March 12, 1934 NEATSEAL I I .\a

m m. V my PRESSED \y B Y 0%,Mm2/Y-MZ TTORNEK Patented Sept. 14, 1937UNITED STATES BAG AND METHOD OF MAKING SAME Charles F. Richard, BattleCreek, Mich, assignor to Johnson Automatic Sealer Co., Ltd., BattleCreek, Mich., a limited partnership association of Michigan ApplicationMarch 12, 1934, Serial No. 715,236

13 Claims.

This invention relates to bags and to methods of making bags, and ismore particularly concerned with bags of polygonal cross section thatare formed from unitary blanks of paper or like material.

It has previously been proposed to make a bag of this general characterby folding a blank about a suitable mandrel, overlapping the end edgesof the blank to form a seem in one of the sides of the bag, tucking andfolding one side edge of the blank to form a bottom for the bag, andthen sealing the seam and bottom by the use of adhesive or, where thematerial of' the blank is self-sealing, by the application of heat. Bagshave also been constructed by wrapping blanks about mandrels in such amanner as to form smooth continuous bottoms for the bags, all of l theseams lying in the side panels of the bags and being formed byoverlapping and sealing the side edges of the blanks. However, in all ofthese bags provided with overlapping seams much difdculty has beenexperienced in attaining a sufficiently tight seal at the seams torender the bags moisture-, airand sift-proof, particularly when saidbags are used for food products of various kinds and as liners forcartons. Where the efficiency of the seal at the seams of a bag dependsentirely upon the degree of adhesion between overlapping portions of theblank, the smallest imperfection in said adhesion renders the sealpractically ineffective, and far greater care must be exercised,resulting in greater expense, in making such a seam than if the emciencyof the seal were obtained by some other 3 factor in addition to adhesionbetween portions of the blank.

It is therefore one of the objects of the present invention to provide abag of novel construction formed from a unitary blank of material andhaving seams lying only in the sides thereof, said seams beingefficiently sealed in an improved manner against the passage of air,moisture and the material with which the bag may be filled.

Another object is to provide a new and eflicient method of making a bagfrom a single blank of material which is characterized by a novel mannerof forming and sealing the seams of said bag.

A further object is to provide a bag of improvedconstruction wherein amore efiicient sealing of the seams is attained as the result of both anovel form of fold of the edges of the blank and adhesion between thefolded portions. Still another object is to provide a novel method ofmaking a bag from a unitary blank of 55 material wherein the seams areclosed and sealed by folding the edge portions of the blank over andover upon themselves and then causing the folded portions to adhere toone another, which method also comprises a new manner of disposing ofthe blank material in excess of that actually utilized in forming thebottom and sides of the bag.

A still further object is to provide both a bag and a method of makingthe same which are improvements over the bags and bag making methods ofthe prior art and which result in a container especially well adaptedfor use either as a liner for cartons or as an individual package forproducts such as foods because of the high moisture-, airand sift-proofqualities of its seams.

These and other objects will appear more fully from a consideration ofthe detailed description of the invention which follows. While only oneembodiment of the bag and method constituting the present invention hasbeen illustrated in the accompanying drawing, it is to be expresslyunderstood that this drawing is for the purpose of illustration only andis not to be construed as defining the scope of the invention, referencebeing had for the latter purpose to the appended claims.

Referring now to the drawing, wherein like reference characters indicatelike parts throughout the several views:

Figs. 1-7 are diagrammatic illustrations of the successive stepsinvolved in the method of making a bag according to the presentinvention, Fig.7 also showing the bag in its completed form.

For purposes of illustration, the drawing shows the various steps in theformation of a quadrilateral bag of rectangular cross section from ablank of self-sealing wax impregnated paper, although it is to bedistinctly understood that the invention is not limited to bags of thisparticular shape or to blanks of waxed paper. Also, while the embodimentof the method illustrated involves the use of a mandrel of suitableconstruction to assist in the folding of the blank, it is obvious thatthe inventive concept of the method is not limited to the use of anyspecific apparatus. As shown in Fig. 1, the first formative step in themethod of the present invention'involves the folding of a blank ofsuitable material, such as provides a smooth continuous bottom and twoopposite smooth continuous sides l2 am. It for the bag. The blank 8 ispreferably of such width that this first folding step leaves the sideedge portions l4 and'l5 thereof projecting beyond the ,edges of themandrel by amounts exceeding onehalf the width of the other two oppositesides It and ll of the mandrel.

After the blank 8 has thus been folded to a substantially U shape, thenext step in the method, indicated in Fig. 2, comprises engaging theblank at substantially the centers of the edges of those parts ofprojecting edge portions l4 and I5 forming the bight of the U, as atpoints i8 and I9, and exerting at said points a-downward force tendingto narrow the distance between the adjacent vertical portions of eachside edge of the blank. At the same time, and while maintaining thedownward pressure at points I 8 and IS, the opposite portions of each ofprojecting edge portions II and I5 of the blank are brought together andcreases are made in the blank against mandrel sides l6 and I! alongparallel lines 20, 2|, 22, 23, 24, 25 26 and 21, as shown in Fig. 3.This second creasing or folding operation forms the other two oppositesides 28 and 29 of the bag and leaves each of said sides with a doublethickness of paper, indicated at 30 and 3|, extending outwardly at rightangles to the plane of said side, and with a triangular flap 32, 33coplanar with said side and extending downwardly below the bottom of themandrel.

At this phase of the method, it will be noted that the bottom and eachof the four side faces of mandrel II are covered by a single thicknessonly of the blank material, and that each of the side edges of the blankis doubled with the doubled portions of each edge lying together andparallel to the lines 20-21 along which the blank is creased.

The next-step in the method according to the present invention is toclose the seams of the bag thus provided in sides 28'and 2! by foldingthe outwardly projecting double thicknesses 30 and 3| over and over uponthemselves and then flattening the over-and-over folded portions intothe planes of the associated sides of the bag. These folding andflattening operations are indicated in Figs. 4, 5, and 6.-

In Fig. 4, the outer halves of projecting edge portions 30 and 3| ofdouble thickness are shown folded through an angle of while in Fig. 5the folding has been continued through an angle of so that the sideedges of the blank lie closely adjacent the blank: material formingsides 28 and 29 of the bag, leaving a quadruple thickness of blankmaterial extending perpendicularly to each of said sides. Fig. 6 showsthe thus folded seam portions folded through another angle of 90 andflattened substantially into the planes of sides 28 and 29. -It will benoted that the side edges of the'blank now lie covered by the foldedseam portions. It is to be understood that projecting edge portions IIIand 3| may be made proportionately longer than those shown in thedrawing, andlor the first folds therein may be 'made nearer to theedges, if it should be desiredthat more than three 90 folds be made inthe folded seam portions.

The formatiosrof the bag may becompleted by folding triangular flaps 32and 33, and the overlying portions of folded and" flattened edgeportions 30 and 3|, baekwardly through 180 into the planes of theirassociated sides 28 and 29. Pressure may now be applied to the foldedseam portions and backwardly turned flaps to tightly compress theoverlying thicknesses of the ball material and sharply crease all of thefolded edges thereof.

Due to the novel manner of forming the folded seams just described,wherein the doubled portions of the side edges of the blank lie togetherand covered by the folded portions of the blank, the seams of the bagare rendered practically sift-proof, and even moisture-proof andair-proof to a substantial extent. However, in order to increase thelatter two qualities to a maximum, the method of the present inventionalso includes the formation of an adhesive seal between the variousoverlying thicknesses of the blank material in the folded seam portionsand backwardly turned flaps. Q

Where the blank 8 is of waxed paper, as in the embodiment disclosed, theadhesive sealing may be readily attained by applying pressure and heatto the desired portions for a sufficient time to cause adhesion of theoverlying thicknesses one to the other through the medium of the sealingmaterial with which the blank is impregnated, as indicated by the legendin Fig. 'I. When the heat sealed portions have cooled sufficiently tovset, the completed bag may be removed from mandrel l l ready for useeither as the inner liner for a carton or as the sole container for anydesired material.

There is thus provided by the present invention both a bag of novelconstruction and a simple and eflicient method of making such a bag froma single blank of material, both of which are characterized by the highquality of the seals at the portions of the bag where the edges of theblank are joined and folded. The bag provided by the present inventionhas a smooth continuous bottom and all but two smooth continuous sides,the two discontinuous sides containing all of the seams necessary forthe formation of the bag. These seams are formed by a novel method ofcreasing and folding the side edge portions of the carton blank, and thehigh degree of tightness of the seams is attributable both to saidfolding and to an adhesive sealing of the folded and overlying portionsof the blank. .By thus rendering the efficiency of the seal dependentupon both folding and adhesion, rather than upon adhesion alone, the bagand bag forming method of the present invention constitute markedimprovements over the bags and methods previously known to the art, andprovide a container which, because of its high moisture-, airandsift-proof qualities, is especially well adapted for use either as aliner for cartons or as an individual package for products such asfoods.

It will be obvious that the invention is not limited either to the exactform of bag shown in the drawing or to the specific steps of the methoddisclosed, but is capable of a variety of embodiments. For example, thebag may be of any desired polygonal cross section, other thanrectangular, and may be made from any suitable material in addition towax impregnated paper. Likewise, the steps of the method may be carriedout independently of apparatus of any specific character, such as themandrel shown, and may be employed in the formation of bags of shapesand materials in addition to those specifically disclosed. Various otherchanges, which will now appear to those skilled in the art, may be madeboth in the form and details of construction of the bag and in thevarious steps of the method of making the same, without departing fromthe spirit of the invention. Reference is therefore to be had to theappended claims for a definition of the limits of the invention.

What is claimed is:

1. A bag of polygonal cross section made from an integral blank ofmaterial comprising an open top, a smooth continuous bottom and at leasttwo opposite smooth continuous sides, each of two other sides havingtherein an over-and-over folded, sealed seam wherein the edges of theblank lie together and covered by the folded portion thereof, each ofsaid folded seam portions lying in substantially the same plane as theassociated side of the bag. s

2. A bag of polygonal cross section made from an integral blank ofmaterial comprising an open top, a smooth continuous bottom and at leasttwo opposite smooth continuous sides, each of 'two other sides havingtherein an over-and-over folded, sealed seam lying in substantially thesame plane therewith and a triangular flap folded back from the bottomedge into the plane of said side, the edges of the blank lying togetherand covered by the folded portions thereof.

3. A bag of polygonal cross section made from an integral blank of waxedpaper comprising an open top, a smooth continuous bottom and at leasttwo opposite smooth continuous sides, each of two other sides havingtherein a seam consist'ing of a double thickness of the blank materialfolded over upon itself, flattened into substantially the same plane asthe associated side of the bag, and sealed through the medium of the waxwith which the paper is impregnated, and wherein the edges of theportions of the blank forming said seams lie together.

4. A quadrilateral bag made of self-sealing material comprising aunitary blank folded on two transverse lines to form a smooth continuousbottom and two smooth continuous sides, the parallel side edges of thethus folded blank being brought together and folded over to form seamsin the other two sides wherein the side edges of the blank lie together,said seams lying in substantially the same planes as the associatedsides of the bag and being substantially hermetically sealed.

5. A quadrilateral bag comprising a unitary blank of material folded ontwo transverse lines to form a smooth continuous bottom and two smoothcontinuous sides, the parallel side edges of the thus folded blank beingbrought together and folded over and over to form seams in the other twosides, and a triangular flap folded back from the bottom edge into theplane of each of said seamed sides and overlying a portion of the seamformed therein, said over-and-over folded seams being substantiallyhermetically sealed and said flaps being sealed to said seamed sides.

6. A bag made from an integral blank of material comprising an open top,a smooth con tinuous bottom and sides which are smooth and continuousexcept for a pair of opposite, overand-over folded, sealed seams whereinthe edges of the blank lie together and covered by the folded portionthereof, each of said folded seam portions lying in substantially thesame plane as the associated side of the bag.

'7. A bag made from an integral blank of selfsealing material comprisingan open top, a smooth continuous bottom and sides having therein a pairof diametrically opposite seams, each of said seams consisting of adouble thickness of the blank material folded over and over upon itself,flattened into substantially the same plane as the associated side ofthe bag, and sealed with the side edges of the blank lying together insaid seam.

8. The method of making a bag from a unitary blank of material whichcomprises folding said blank into substantially U shape to form a smoothcontinuous bottom for the bag, bringing the adjacent edge portions ofthe blank together and folding them along parallel lines to form thesides of the bag and to provide the bag with a pair of opposite seamportionseach consisting of a. double thickness of blank materialextending outwardly from the bag, folding each of said doublethicknesses over upon itself to close the seams, flattening each of thethus folded seam portions into the plane of the associated side portionof the bag, and adhesively scaling to one another the overlyingthicknesses of said folded and flattened seam portions.

9. The method of making a bag of polygonal cross section from a unitaryblank of material which comprises folding said blank along two paralleltransverse lines into substantially U shape to form the bottom and twosides of the bag, bringing the adjacent edge portions of the blanktogether and folding them along parallel lines to form the other sidesof the bag and to provide each of two of said sides with a doublethickness of material extending laterally outwardly from the center linethereof, folding each of said laterally extending, double thicknessesover' upon itself to close the seams of the bag, and flattening the thusfolded portions into the planes of the associated sides.

10. The method of making a bag of polygonal cross section from a unitaryblank of material which comprises folding said blank along two paralleltransverse lines into substantially U shape, engaging the material atthe middle of the edges of the bight of the U and exerting a downwardforce thereon while bringing the adjacent edge portions of the blanktogether and folding them along parallel lines to form the other sidesof the bag and to provide each of two of said sides with a doublethickness of material extending laterally outwardly from the center linethereof andwithatriangular flapextending downwardly from the bottom edgethereof and lying in the same plane therewith, folding each of saidlaterally extending double thicknessesover upon itself to close theseams of the bag, and flattening thethusfolded portions andturningthetriangular flaps back through 180 into the planes of theirassociated sides.

11.- The method of making a bag of polygonal cross section from aunitary blank of material which comprises folding said blank along twoparallelv transverse lines into substantially U shape, engaging thematerial at the middle of the edges of the bight of the U and exerting adownward force thereon while bringing the adjacent edge portions of theblank together and folding them along parallel lines to form the othersides of the bag and to provide each of two of said sides with a doublethickness of material extending laterally outwardly from the center linethereof and with a triangular flap extending downwardly from the bottomedge thereof and lying in the same plane therewith, folding each of saidlaterally extending double thicknesses over upon itself to close theseams of the bag, flattening the thus folded portions and turning thetriangular flaps back through 180 into the planes of their associatedsides, and adhesively sealing the seams and folded flaps.

12.Themethodofmakingabegfromaunitary blank of self-sealing materialwhich comprises folding the blank about three of the faces of a mandrelof quadrilateral cross section to form the bottom andtwo of the oppositesidu of the bag, the side edges of the blank projecting beyond the edgesof said three faces of the mandrel, folding said projecting sideportions of the blank against the other two opposite faces of themandrellmtilthelatterareeoveredbyasinglethickness only of theblankmaterial to form the other two sides of the bag, the material inexcess of that necessary to cover said faces extending at right anglesthereto with the edges of the blank outeredge portions of the blankprojecting beyond the edges of the mandrel by amounts exceeding onehalfthe width of the other two opposite sides thereof, engaging theprojecting edges of the portion of the blank forming the bottom of thebag and exerting thereon a downward force while bringing the parallelprojecting edge portions of the blank together and creasing them againstthe mandrel to form the other two opposite sides of the bag, saidcreasing operation leaving each of said last named sides with a doublethickness of paper extending outwardly atrlght angles thereto and with atriangular flap coplanar therewith extending downwardly below the bottomof the mandrel, folding each of said outwardly extending doublethicknesses of paper over upon itself through 180 to close the seams ofthe bag, flattening said folded seam portions into the planes of theassociated sides, turning the triangular flaps back through 180 into theplanes of said sides, and sealing the overlying thicknesses of paper insaid folded seam portions and backwardly turned flaps to one another andto said bag sides by the application of heat thereto.

CHARLES F. RICHARD.

